Package org.apache.drill.exec.planner.physical

Class HashPrelUtil

java.lang.Object

org.apache.drill.exec.planner.physical.HashPrelUtil

public class HashPrelUtil
extends Object

Contains utility methods for creating hash expression for either distribution (in PartitionSender) or for HashTable.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	HashPrelUtil.HashExpressionCreatorHelper<T>	Interface for creating different forms of hash expression types.
static class	HashPrelUtil.RexNodeBasedHashExpressionCreatorHelper

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DIST_SEED
static final String	HASH_EXPR_NAME
static HashPrelUtil.HashExpressionCreatorHelper<LogicalExpression>	HASH_HELPER_LOGICAL_EXPRESSION	Implementation of HashPrelUtil.HashExpressionCreatorHelper for LogicalExpression type.

Constructor Summary

Constructors

Constructor	Description
HashPrelUtil()

Method Summary

Modifier and Type	Method	Description
static <T> T	createHash64Expression(List<T> inputExprs, T seed, HashPrelUtil.HashExpressionCreatorHelper<T> helper, boolean hashAsDouble)	Create hash expression based on the given input fields.
static <T> T	createHashBasedPartitionExpression(List<T> distFields, T seed, HashPrelUtil.HashExpressionCreatorHelper<T> helper)	Create hash based partition expression based on the given distribution fields.
static <T> T	createHashExpression(List<T> inputExprs, T seed, HashPrelUtil.HashExpressionCreatorHelper<T> helper, boolean hashAsDouble)	Create hash expression based on the given input fields.
static LogicalExpression	getHash64Expression(LogicalExpression field, LogicalExpression seed, boolean hashAsDouble)	Creates hash expression for input field and seed.
static LogicalExpression	getHashExpression(List<DrillDistributionTrait.DistributionField> fields, org.apache.calcite.rel.type.RelDataType rowType)	Create a distribution hash expression.
static LogicalExpression	getHashExpression(LogicalExpression field, LogicalExpression seed, boolean hashAsDouble)	Creates hash expression for input field and seed.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

HASH_EXPR_NAME

public static final String HASH_EXPR_NAME

See Also:

• Constant Field Values

DIST_SEED

public static final int DIST_SEED

See Also:

• Constant Field Values

HASH_HELPER_LOGICAL_EXPRESSION

public static HashPrelUtil.HashExpressionCreatorHelper<LogicalExpression> HASH_HELPER_LOGICAL_EXPRESSION

Implementation of HashPrelUtil.HashExpressionCreatorHelper for LogicalExpression type.

Constructor Details

HashPrelUtil

public HashPrelUtil()

Method Details

createHashBasedPartitionExpression

public static <T> T createHashBasedPartitionExpression(List<T> distFields,
 T seed,
 HashPrelUtil.HashExpressionCreatorHelper<T> helper)

Create hash based partition expression based on the given distribution fields.

Type Parameters:

T - Input and output expression type. Currently it could be either RexNode or LogicalExpression

Parameters:

distFields - Field list based on which the distribution partition expression is constructed.

helper - Implementation of HashPrelUtil.HashExpressionCreatorHelper which is used to create function expressions.

Returns:

createHashExpression

public static <T> T createHashExpression(List<T> inputExprs,
 T seed,
 HashPrelUtil.HashExpressionCreatorHelper<T> helper,
 boolean hashAsDouble)

Create hash expression based on the given input fields.

Type Parameters:

T - Input and output expression type. Currently it could be either RexNode or LogicalExpression

Parameters:

inputExprs - Expression list based on which the hash expression is constructed.

helper - Implementation of HashPrelUtil.HashExpressionCreatorHelper which is used to create function expressions.

hashAsDouble - Whether to use the hash as double function or regular hash64 function.

Returns:

createHash64Expression

public static <T> T createHash64Expression(List<T> inputExprs,
 T seed,
 HashPrelUtil.HashExpressionCreatorHelper<T> helper,
 boolean hashAsDouble)

Create hash expression based on the given input fields.

Type Parameters:

T - Input and output expression type. Currently it could be either RexNode or LogicalExpression

Parameters:

inputExprs - Expression list based on which the hash expression is constructed.

helper - Implementation of HashPrelUtil.HashExpressionCreatorHelper which is used to create function expressions.

hashAsDouble - Whether to use the hash as double function or regular hash64 function.

Returns:

getHash64Expression

public static LogicalExpression getHash64Expression(LogicalExpression field,
 LogicalExpression seed,
 boolean hashAsDouble)

Creates hash expression for input field and seed.

Parameters:

field - field expression

seed - seed expression

hashAsDouble - whether to use the hash as double function or regular hash64 function

Returns:

hash expression

getHashExpression

public static LogicalExpression getHashExpression(LogicalExpression field,
 LogicalExpression seed,
 boolean hashAsDouble)

Creates hash expression for input field and seed.

Parameters:

field - field expression

seed - seed expression

hashAsDouble - whether to use the hash as double function or regular hash64 function

Returns:

hash expression

getHashExpression

public static LogicalExpression getHashExpression(List<DrillDistributionTrait.DistributionField> fields,
 org.apache.calcite.rel.type.RelDataType rowType)

Create a distribution hash expression.

Parameters:

fields - Distribution fields

rowType - Row type

Returns:

distribution hash expression